Modulation Device and Pulse Wave Generation Device

1. A modulation device for modulating a frequency or a phase of a carrier signal according to a baseband signal, the modulation device comprising: a signal selection circuit selecting two carrier signals from a plurality of carrier signals having the same frequency according to a defined control signal and outputting the selected carrier signals; a phase interpolator adjusting the phase in smaller units than a phase difference between the plurality of carrier signals according to the control signal and modulating the frequency or the phase of the carrier signal according to the baseband signal based on the carrier signals selected by the signal selection circuit to generate a carrier wave signal; and a phase modulation signal generation circuit generating the control signal that is to control the signal selection circuit to select the two carrier signals and the phase interpolator to generate the carrier wave signal, wherein the plurality of carrier signals have the same phase difference, and wherein, when i is an integer from 1 to m, N 1 , N 2 , . . . , Nm are an arbitrary integer combination, wherein N 1 +N 2 + . . . +Nm=k, and Ti is an arbitrary combination, wherein T 1 +T 2 + . . . Tm=pb−pa, the phase modulation signal generation circuit switches the control signal corresponding to the baseband signal having a period k times the period of the carrier signal in synchronization with a phase switching clock in which the carrier signal rises at every Ni times, wherein, when the phase of the carrier wave signal is changed from 360°×pa to 360°×pb with respect to the phase of the carrier signal according to the baseband signal, a phase difference that is to be switched in every Ni period of the carrier wave signal is 360°×Ti.

2. The modulation device according to claim 1 , wherein the phase modulation signal generation circuit switches the control signal corresponding to the baseband signal in synchronization with a phase switching clock which is the same frequency as the carrier signal to switch the phase of the carrier wave signal in every period, wherein, when the frequency of the carrier signal is fc and the modulation frequency is Δfc, a phase change value that is to be switched in every period of the carrier wave signal is 360°×Δfc/(fc+Δfc).

3. The modulation device according to claim 1 , wherein the phase modulation signal generation circuit switches the control signal corresponding to the baseband signal in synchronization with a phase switching clock which is a frequency 1/R times the frequency of the carrier signal to switch the phase of the carrier wave signal in every R period, wherein, when the frequency of the carrier signal is fc and the modulation frequency is Δfc, a phase change value that is to be switched in every R period of the carrier wave signal is R×360°×Δfc/(fc+Δfc).

4. A pulse wave generation device comprising: an S phase clock converter circuit including S sets of a signal selection circuit and a phase interpolator, as recited in claim 1 , and outputting S carrier signals having the same frequency and a phase difference of 360°/S; and a duty ratio converter circuit generating S carrier wave signals having different duty ratios in units of 1/S from the S phase carrier signals output from the S phase clock converter circuit.